Magnetic cassette tapes are useful for the storage of a variety of information (i.e., analog or digital). Magnetic tape cassettes, for example, may be used to store information derived, inter alia, from such devices as video and/or audio recorders.
The medium used for the storage of information within a magnetic cassette tape is typically in the form of a flexible strip of a non-magnetic material (i.e., plastic or mylar) coated with particles of a magnetizable metal oxide. Information is recorded on the tape during use by passing the tape over a recording head which magnetizes the particles of the oxide in a manner representative of the information to be stored. During recordation of information, the tape is passed from a first reel of the cassette to a second reel.
A cassette housing (cassette) of a magnetic tape cassette provides an alignment and support structure for the two reels as well as a means for supporting, aligning and controlling the tape as it passes between the two reels during recordation and playback of the stored information. A reel spring is mounted within the cassette on a first side which engages and biases the reels towards an opposing side of the cassette.
To protect the tape of a magnetic tape cassette from stray sources of magnetism, prior art cassette enclosures and reels have been constructed of non-magnetic materials (i.e., plastic). To further protect the tape from magnetism, the prior art has taught that the reel springs must be constructed of a non-magnetic material such as stainless steel or aluminum. The prior art has taught that such practices were necessary for the reliable operation of magnetic cassette tapes.
While the prior art use of stainless steels and aluminum in the construction of reel springs has been effective, such materials are relatively expensive and difficult to work with. Because of the importance of magnetic cassette tapes a need exists for means of using a less expensive, more workable material for the construction of reel springs.